Chp 2 - CogNeuro Flashcards
Capgras’ syndrome
- Issue with ventral “what” pathway, no emotional connection
- When look at things, goes thru temporal lobe, need to connect it to the amygdala, contains the emotion response
- Fibre going to the amygdala are cut
- The auditory is not affected (Fine during phone call)
- Temporal part that is related to the auditory functions that was not damaged
- Think people living with them are imposters/ think the home is not their home
- Can happen in parkinsons
Phrenology
involved examination and
measurement of the skull and its individual topography.
(the detailed study of the shape and size of the cranium as a supposed indication of character and mental abilities.)
Major assumptions:
* The brain is the organ of the mind
* The brain is modular and functions are localized
* Brain functioning and specific traits are innate
* Individual differences due to differentially developed areas in the brain
Name 3 methods of studying the brain
- Animal models
- Human case studies
- Brain Imaging
Name 2 ways they did animal models to study the brain
→ Ablation/lesion studies
→ Single cell recording
Hindbrain and mid brain are the ______ parts of the brain
oldest
What are the structures in the hindbrain? (3)
- Pons
- Medulla
- Cerebellum
Medulla
- Located just above the spinal cord
- Heart rate & respiration
- Thoroughfare for sensory information
Pons
- Lies on each side of the medulla (ventral and anterior)
- Regulate sleep, dreaming, respiration
- Axons from each half of the brain cross to the opposite side of the spinal cord
Reticular formation (Midbrain)
Responsible for consciousness, wakefulness, arousal and attention
If damaged: coma
If stimulate cat’s RF when they are awake, they go to sleep
What are the main structures in the forebrain?
- Thalamus
- Hypothalamus
- Pituitary Gland
- Amygdala
- Hippocampus
Thalamus
- Sensory switchboard
- Routes sensory information to appropriate place
- (e.g., visual goes to visual centres; auditory to auditory centres)
- All senses (except for olfaction) are routed through the thalamus
Hypothalamus
- Major role in controlling biological drives
- Sexual behaviour, eating, drinking, circadian rhythms, aggression, emotion
- Connection with pituitary gland that controls hormones
- Damage can disrupt all these behaviours
Amygdala
- Organizes emotional responses
- Especially those linked to aggression and fear
- Stimulation of amygdala in animal studies leads to snarling behaviour
- eg. patient S.M.: near complete bilateral destruction of the amygdala, dubbed “the woman with no fear”, preserved (and even enhanced) fear response to CO2 inhalation
Hippocampus
- Forming & retrieving memories
- Damage to hippocampus can result in profound amnesia
- eg. patient H.M.: anterograde amnesia (inability to form new long-term memories)
Pituitary gland
- hormone-producing gland found at the base of the hypothalamus
- Released in response to sex and motivated behaviour
Cerebral Cortex
- More highly developed in humans than other species
- responsible for the higher-level processes of the human brain, including language, memory, reasoning, thought, learning, decision-making, emotion, intelligence and personality
Without cerebral cortex: cant use lang and specific funcition
Four Lobes of the Cerebral Cortex
- Frontal
- Occipital
- Parietal
- Temporal
Occipital Lobe
- Highly responsible for visual input
- Located at the posterior end of the cortex
- Known as the striate cortex or the primary visual cortex
- Visual Cortex: Brodmann area 17
Parietal Lobe
- Essential for spatial information as well as numerical information
- Contains the postcentral gyrus (“primary somatosensory cortex”)
- Primary target for touch sensations and information from muscle-stretch receptors and joint receptors
Temporal Lobe
- Lateral portion of each hemisphere: Target for auditory information and essential for processing spoken language (usually LEFT)
- Responsible for complex aspects of vision, including movement and some emotional and motivational behaviors: Klüver-Bucy syndrome associated with temporal lobe damage
Premotor Cortex
- Abstract thinking and planning
- Ability to remember recent events and information (“working memory”)
- Planning and consequences
- High level functioning
- Complex long term planning
- Impulse control
Damage:
- Say inappropriate things
- Lack of empathy
-Last part of the brain to develop (tend to be developed till 25)
- Brain scan of murderers tend to have lower activities in prefrontal cortex
What does the Frontal Lobe include? (2)
- Precentral gyrus (primary motor cortex): control of motor movement
- Prefrontal cortex
- is a not very understood area
Primary Motor Cortex
- Responsible for control of specific areas of the opposite side of the body
- Active when people intend a movement
- “orders” an outcome
- also active when you imagine, remember movements or understand verbs related to movements
- Fine motor control contributes to more mapping in the primary motor cortex
Somatosensory Cortex
- Receives specific sense information from opposite side of body
- At least one specific area for each sense
- Located in parietal lobe
More sensory receptors in some areas:
Malleable:
If engage in some activities, may end up with more sensory/ motor receptors
e.g. violinist
Right side of the brain contributes due to the left hand
- Evidence of Neuroplasticity
All sense except for hearing is processed ________ly
contralaterally
Insula
-not very understood
- Might be related to sense of self-awareness
corpus callousum
- How the 2 hemispheres communicate
- Help with epilepsy (grand mal)
- Subject to change due to neuroplasticity
- Tend to be larger in musicians
gyri
bumps
Sulci
grooves
Name the 5 brain imaging techniques mentioned in class.
- Electroencephalography (EEG)
- Magnetoencephalography (MEG)
- Positron Emission Tomography (PET)
- Functional Magnetic Resonance Imaging (fMRI)
- Functional Near-Infrared Spectroscopy (fNIRS)
Name the 2 brain stimulation techniques.
TMS & tDCS
Name the types of LTM
Declarative (Explicit) Memory (can be verbalized)
- Episodic
- Semantic
Nondeclarative (Implicit) Memory
Episodic memory
Personal experiences (‘episodes’ of your life)
Semantic memory
General factual knowledge
Nondeclarative (Implicit) Memory
- Procedural
- Reflected in motor / cognitive skills and actions
- Some classically conditioned responses
- Perceptual priming
Dissociation
Disruption in one component of mental functioning but no impairment of the other
Double Dissociation
- Complete separation
- Brain lesion that cause disruption in process A doesn’t affect process B, and lesion that cause damage in process B doesn’t affect process A
Semantic retrieval
-Retrieve meaning of a concept
Lexical retrieval
Finding the name for the concept
Neuron
Specialized cell that receives and transmits a neural impulse
Neuron Structure (7)
- Cell body
- Nucleus
- Dendrites (input)
- Myelin sheath
- Axon
- Axon hillock
- Axon terminal (buttons)
Myelin sheath
- Speed neural communication
- Nerve impulses jump through nodes
- Produced by glial cells
Multiple sclerosis
Suffering from damage to the myelin
Sensory-Motor Reflex Arc
Receptor cells
- React to physical stimulus and trigger a pattern of firing down sensory neurons
- Neuron tracts pass the message along spinal cord
Interneurons
- In the CNS, spinal cord to brain
- Routes a message up the spinal cord and into the brain
Electrical Neural Communication/ Action potential
- Occur within the interior of the neuron
- Resting charge of -70mV
- When stimulated, depolarization of the electrical potential, “fire”
- Change to +40mV
- Sodium(+) ions enter the interior of the cells as the ion gates on the cell membrane open in sequence, cause action potential to be electrically positive
- Potassium(+) ions being forced out of the cell, renders base charge of the neuron negative again
Propagated
the movement of an action potential from dendrites, through soma, and down axon
All-or-none principle
The idea of that either a neuron fires or it does not, with all action potentials being the same
Chemical Neural Communication
The impulse of the action potential within a neuron terminates at the axon terminals and is taken up by the dendrites of the next neurons in the pathway
Synapse
region where the axon terminals of one neuron and the dendrites of another come together
Synapse as a verb
meaning it passes its message on to that other neuron
Divergence
in the brain, any single neuron synapses on a large number of other neurons (on anywhere from 100 to as many as 15000 other neurons)
Convergence
Many diff neurons can synapse on a single destination neuron
How Neurons Communicate: Synaptic Transmission
- Neurons do not make physical contact
- Communicate with chemicals
- The firing (presynaptic) neuron releases chemicals called neurotransmitters into the synaptic cleft
Neurotransmitters
- Chemicals produced by neurons
- Synthesized inside neurons
- Stored in synaptic vesicles
- Released by presynaptic neuron
- Bind to receptor sites in postsynaptic neuron
- Neurotransmitters bind only to specific sites
Excitation and Inhibition
Successful neurotransmitter binding to a postsynaptic neuron does not necessarily trigger an action potential!
Excitatory neurotransmitters
- Depolarizes neuron
- Stimulates flow of Na+ ions
- Increases likelihood of action potential
Inhibitory neurotransmitters
- Hyperpolarizes neuron
- Stimulates K+ to flow out
- Decreases likelihood of action potential
Neuromodulators
- Work in conjunction with other chemicals
- Accentuates or diminish effects of neurotransmitter
- Excitatory neurotransmitter more excitatory, inhib more inhib
The neurotransmitters that have major influences are on cognitive processes, e.g. learning and memory (2)
- Acetylcholine
- Norepinephrine
Acetylcholine
- Essential role in normal learning and memory
- Related to long-term potentiation
- Low levels related to Alzheimer’s disease, learning/ memory deficit
Glutamate
- Excitatory neurotransmitter
- Important for creating and strengthening the connections between neurons (how we learn)
GABA
- Inhibitory neurotransmitter
- Weaking the connections between neurons
- Kinda like the opp of glutamate
GABA
- Inhibitory neurotransmitter
- Weaking the connections between neurons
- Kinda like the opp of glutamate
Contralaterality
- Principle that control of one side of the body is localised in the opposite hemisphere of the brain
Hemisphere Specialization
- Principle that each cerebral hemisphere has specialised functions and abilities
Cerebral lateralization
- Different functions or actions within the brain tend to be to localized one or the other hemisphere
CT Scan
- Computerized Axial Tomography
- X-ray
- Quick assessment of general brain structure
MRI
- Magnetic Resonance Imaging
- Machine creates a very strong magnetic field
- Used to look at the distribution of molecules of a certain type
- E.g. see brain structure, look at distribution of water molecules
- Very clear resolution
- Cannot work with people with metal implants
Single cell recording
- Looks at how the firing rate of an individual cell changes, by seeing whether it fires more or less often as a function of the given task
- Typically used on animals
- Very invasive
EEG
- Electroencephalogram Recording
- Not invasive
- Electrodes placed on the scalp, device records the pattern of brain waves
Event-Related Potential (ERPs)
- The momentary changes in electrical activity of the brain when a particular stimulus is presented to a person
- N400 for sematic violations
TMS
- Transcranial Magnetic Stimulation
- Apparatus is positioned near a person’s head with a part of the brain targeted
- Turned on: produces magnetic field that stimulates/ disrupts the electrical activity in a part of a person’s brain
- Temporary lesion
PET Scans
- Positron emission tomography
- Injected with radioactive isotope that is taken up in the bloodstream (Isotope is minimal impact)
- Person is placed into scanner and asked to do a kind of task
- Found certain parts of the brain works harder than they normally to
- Part of the brain will “light up” in the PET scan image
PET Scans
- Positron emission tomography
- Injected with radioactive isotope that is taken up in the bloodstream (Isotope is minimal impact)
- Person is placed into scanner and asked to do a kind of task
- Found certain parts of the brain works harder than they normally to
- Part of the brain will “light up” in the PET scan image
fMRI
- Functional
- Yields images of the functioning of the brain
- MRI magnet to isolate molecules,
- BOLD signal: oxygen to assess where increased blood is flowing in the brain, indicate heightened neural activity
Lesions
- Usually on animals, patients with med conditions
- Sometimes reveals secrets of cog processes
Direct Stimulation
- Patient remained conscious
- Applied minute electrical charges to the exposed brain
- Patients asked to answer questions or report out thoughts and mem
- Compare the patient’s reports with diff regions that are stimulated, surgeon can dev a map of cerebral functioning
